1. Field of the Invention
Embodiments of the present invention relate to a wiring structure in a semiconductor device and a method of forming a wiring structure in a semiconductor device. More particularly, embodiments of the present invention relate to electrical connections of a wiring structure in a semiconductor memory device, and a method of forming the wiring structure.
2. Description of the Related Art
As semiconductor devices become more highly integrated, the size of wiring within the semiconductor devices, as well as the intervals between adjacent wirings, have been considerably reduced. Accordingly, the wiring of highly integrated semiconductor devices may not have desired low resistance and electrical shorts may be generated between adjacent wirings having minute sizes.
In forming minute wiring and a plug (or contact) contacting the wiring, alignment errors may occur between the wiring and the plug, causing an electrical failure between the plug and the wiring, or between the plug and an adjacent wiring. Design requirements for smaller semiconductor devices may cause more frequent electrical failures between plugs and wiring. As a result, semiconductor devices may have poor electrical characteristics and deteriorated reliability.
Accordingly, plugs or contacts having enlarged lower portions have been developed to improve the electrical connection between the plugs or contacts and the wiring in semiconductor devices. However, a plug having an enlarged lower portion may also contact wiring other than the intended wiring, causing an electrical short between the plug and unintended (adjacent) wiring, which likewise deteriorates electrical characteristics and reliability of semiconductor devices.